Modeling the Effects of Outdoor Gasonline Powered Generator Use on Indoor Carbon Monoxide Exposures.
Modeling the Effects of Outdoor Gasonline Powered
Generator Use on Indoor Carbon Monoxide Exposures.
(1082 K)
Wang, L.; Emmerich, S. J.
NIST Technical Note 1637; NIST TN 1637; 23 p. August
2009.
Keywords:
gasoline; carbon monoxide; exposure; generators;
computational fluid dynamics; air quality; health
hazards; air flow; simulation; poisons; safety;
scenarios; power cords; temperature; wind effects;
windows; wind velocity; equations
Abstract:
The U.S. Centers for Disease Control and Prevention
(CDC) has reported that up to half of non-fatal CO
poisoning incidents during the hurricane seasons in 2004
and 2005 involved generators operated outdoors but
within seven feet of the home. The guidance provided on
the safe operating distance of a generator is often
neither specific nor consistent. Furthermore, some
generator manufacturers recommend the use of extension
cords to be "as short as possible, preferably less than
15 feet long, to prevent voltage drop and possible
overheating of wires." However, the use of short
extension cords may result in placement of the generator
too close to the home to reduce the likelihood of the
entry of CO. This study modeled multiple scenarios of a
portable generator operated outdoors using the CaNT AM
indoor air quality model coupled with a computational
fluid dynamics (CFD) model to predict CO concentrations
near and within a home. The simulation cases included
both human-controllable factors (e.g., generator
location and exhaust direction and window opening size)
and non-controllable factors (e.g., wind, temperature,
and house dimensions). For the house modeled in this
study, a generator positioned 4.6 m (15 feet) away from
open windows may not be far enough to limit CO entry
into the house. It was also found that winds
perpendicular to the open window
resulted in more CO infiltration than winds at an angle,
and lower wind speed generally led to more CO entry. To
reduce CO entry, the generator should ideally be
positioned outside of airflow recirculation region near
the open windows.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899